In wireless communication systems base stations and wireless communication stations communicate with each other using radio frequency signals that are transmitted and received using antennas. Conventionally, base stations and wireless communication stations used a single antenna for transmitting and receiving signals. Recently, multiple input-multiple output (MIMO) techniques have been employed in which multiple antennas are used for transmitting and receiving signals. Processing circuitry coupled to the multiple antennas combine the signals received over the antennas and/or provide copies of the signals to the multiple antennas for transmission.